In order to provide more power with an internal combustion engine, without changing any of its integral components, such as cam shafts, cylinder heads, pistons, etc., it is possible to supply a larger volume of oxygen-bearing air and fuel at the proper ratio to the cylinders. The induction of this larger volume of oxygen/fuel mixture produces more power because on each cycle of the engine, more oxygen and fuel is available to be burned, which is a direct relationship to the power output generated by the engine.
This can be done in several ways, such as by using turbo-chargers and blowers to increase the inlet pressure of the fuel/air mixture delivered to the combustion cylinders, or by injecting nitrous oxide into the inlet manifold so as to increase the amount of oxygen delivered to the combustion cylinders. Both turbos and blowers induce a mixture of fuel and atmospheric air to move at higher pressure to the cylinders. The least costly of these three procedures is the use of nitrous oxide injection.
A typical nitrous oxide system induces both fuel and oxygen-rich nitrous oxide into the engine at a desired ratio to produce increased power without damage to any of the components of the engine. The nitrous oxide is injected with the fuel into the inlet manifold in order to supply the oxygen that is required to complete the combustion of the fuel in the combustion cylinders. However, if this ratio is not balanced correctly, two things can result. First, if the mixture of nitrous oxide and fuel is too rich (too much fuel compared to the nitrous oxide), complete combustion will not occur of the fuel and optimal power of the engine will not be produced. Second, if the mixture is too lean (too little fuel compared to the nitrous oxide), the combustion will produce too much heat and there is a likelihood of damage to the engine.
The ratio of the fuel to the nitrous oxide is controlled by limiting the size of the orifice in the supply lines of both the fuel and the nitrous oxide leading to the injection nozzle, and by controlling the pressure of both the fuel and the nitrous oxide delivered to the injection nozzle.
The practice of using nozzles in various configurations in fuel supply systems for engines as generally described above is well known in the art. However, there are problems associated with the prior art nozzle configurations. First, nitrous oxide usually is supplied at a high pressure, up to 1,000 psig in a liquid state. When the nitrous oxide is moved through its nozzle, the pressure of the nitrous oxide reduces radically from very high pressure to below atmospheric pressure, and the nitrous oxide changes state from liquid to gas. This results in a radical absorption of heat, and the nozzle structure tends to assume a temperature lower than the level of freezing for water, and the moisture carried in the stream of air past the nozzle tends to condense and freeze on the nozzle. This results in an accumulation of frost and ice on and about the nozzle which has the potential of blocking the outlet ports of both the fuel and the nitrous oxide, together with changing the pattern of flow of the fuel and nitrous oxide through the nozzle ports. Obviously, this has the potential of changing the degree of atomization of the fuel, and of changing the volume, direction and velocity of flow of both the nitrous oxide and fuel into the manifold, all of which can change the performance of the internal combustion engine.
Thus, it would be desirable to maintain the nitrous oxide in its liquid state, preferably at a substantially constant temperature, as the nitrous oxide flows through the nozzle and into the air inlet manifold, with the nitrous oxide being permitted to change from its liquid state to its gaseous state as it emerges from the nozzle opening and moves into the stream of air flowing through the manifold. This tends to cause the nitrous oxide to change state as and after it emerges from the nozzle and as it enters the air stream. Further, it is desirable to inject the fuel, such as gasoline, directly into the stream of nitrous oxide as it changes state so that the natural turbulence and temperature change caused by the change of state of the nitrous oxide functions to assist in the atomization of the fuel, resulting in increased fuel mixing in the air stream as well as resulting in better ignition of the fuel in the combustion chambers.
Further, it is desirable to form a zone of low pressure about the nozzle tip, where the nitrous oxide emerges from the nozzle, so as to tend to draw the nitrous oxide into the zone of low pressure and away from the nozzle as the nitrous oxide emerges from the nozzle and changes from liquid to gas. This tends to displace the effects of the radical change of temperature of the nitrous oxide, so that it is displaced from the nozzle and has less tendency to reduce the temperature of the nozzle itself, resulting in less likelihood of frost accumulating on the nozzle and of the flow from the nozzle becoming blocked. Further, the low pressure at the nozzle tip tends to help atomize the fuel injected into the zone of low pressure.